As President Donald Trump seeks to deny the idea he is looking to fire special counsel Robert Mueller, a growing chorus of voices in Congress are warning the president how bad that would be for the country’s democracy — and are considering ways to protect the Justice Department-appointed investigator.

After an FBI raid on his personal attorney Michael Cohen’s office earlier this week, Mr Trump linked it to Mr Mueller’s investigation into Russian meddling in the 2016 election, calling it a “TOTAL WITCH HUNT” and claiming that attorney-client privilege “is dead”. But on Thursday, he was challenging reports that he considered firing Mr Mueller as recently as December.

“If I wanted to fire Robert Mueller in December, as reported by the Failing New York Times, I would have fired him,” Mr Trump’s account tweeted Thursday. “Just more Fake News from a biased newspaper!”

Mr Trump also appeared to take on a more conciliatory tone over the investigation, even as reports swirled that an interview between Mr Trump and Mr Mueller, which the president has repeatedly said he is willing to do, looks a far dimmer possibility in the wake of the Cohen raid.

“I have agreed with the historically cooperative, displayed approach that we have engaged in with Robert Mueller (Unlike the Clintons!),” Mr Trump tweeted. “I have full confidence in [White House Counsel] Ty Cobb … and have been fully advised throughout each phase of this process.”

His comments came after Republican Speaker of the House Paul Ryan delivered a feeble denunciation of the president’s anti-Mueller rhetoric, and after Senator Orrin Hatch — the longest serving Republican in the Senate — warned that Trump allies who might be telling the president to fire Mr Mueller to cut it out.

“Anyone advising the president — in public or over the airwaves — to fire Bob Mueller does not have the president or the nation’s best interest at heart,” Mr Hatch’s Twitter account posted. “Full stop.”

“I obviously don’t think he should do that,” Mr Ryan said during an appearance on CBS, referring to firing Mr Mueller. “He knows what I think about that. And I think Bob Mueller and the career professionals at the [Department of Justice] should be left to do their jobs.”

A bipartisan group of senators on that chamber’s Judiciary Committee have pushed for a vote on a measure that would protect Mr Mueller’s job by imposing restrictions on the president’s ability to fire him.

The Senate measure — sponsored by Republicans Thom Tillis and Lindsey Graham, and Democrats Chris Coons and Cory Booker — would write into law Justice Department regulations that say a special counsel can only be fired for good cause. The committee’s chairman, Republican Chuck Grassley, says that the measure could see a vote as soon as April 26.

Whether there are legal protections in place or not, firing Mr Mueller could have tremendous political consequences for the president.

Political activist groups have already signed up around 300,000 people to be ready for a swift demonstration of anger to any attempt to get rid of Mr Mueller. Those efforts are being spearheaded by the liberal group MoveOn.org, which has a list of planned rallies in all 50 states and Puerto Rico should the special counsel be ousted.

“Donald Trump could be preparing to put himself above the law. We won’t allow it,” the group’s “rapid response” plan on the website reads. “Our response in the hours following a potential power grab will dictate what happens next — whether Congress will stand up to Trump or alls him to move our democracy toward authoritarianism.”

Several Republicans have indicated they think firing Mr Mueller would be the end of Mr Trump’s presidency. At the very least, the decision would give Democrats political cover to pursue possible impeachment charges should they gain control of the House and Senate in November’s midterm elections.

“I think it’d be devastating,” former Watergate prosecution lawyer Nick Ackerman said of a possible Mueller firing, having seen former President Richard Nixon ultimately resign months after a similar move in 1973.